Tubeless bicycle wheel bead lock

ABSTRACT

A vehicle wheel comprises a wheel rim having first and second sidewalls defining a rim trough, a tire having a tire bead positioned in the rim trough in engagement with the first sidewall, and a bead lock positioned in the rim trough adjacent the tire bead. The bead lock is movable between a locked position and an unlocked position. The bead lock includes an actuator positioned in the opening and including an exposed portion accessible from outside the wheel. The bead lock can further include a band positioned in the rim trough and including two free ends movable relative to each other. The bead lock can further include a tightening mechanism secured to the two free ends. For example, the tightening mechanism can include a winch and a cable wrapped around the winch and secured to one of the free ends.

The present invention relates generally to bicycle wheels, andparticularly to a system for locking a tire bead into engagement with abicycle rim.

Pneumatic bicycle wheels commonly include a hub, spokes extendingradially from the hub, a rim secured to the outer ends of the spokes,and a tire mounted on the rim. While many bicycle wheels include aninner tube between the tire and rim for holding pressurized air, somebicycle rims eliminate the inner tube and instead create a sealedchamber between the tire and the rim. In order to create such a“tubeless” wheel, it is important to have an airtight seal between thetire bead and the sidewalls of the rim. In tubeless wheels, the internalair pressure presses and holds the tire bead in engagement with the rim.

In order to create a proper seal in a tubeless wheel, a precise fit isdesired between the tire bead and the rim. Some rims use a small lip tokeep the tire in place. The standard fit between a tubeless tire and arim works well under easy riding with medium to high tire pressures.This system, however, will not work well under extreme cornering loadsor when tire pressures are low. High cornering loads can cause the tirebead to stretch and lift off of the rim's bead seat and cause air toescape, or completely jump off the rim in extreme conditions. Low tirepressures are often desirable on bicycles for maximum traction andsmoother riding experiences. However, such low-pressure tires have beenknown to lose pressure when the tire bead separates from the rim becausethere is insufficient air pressure holding the tire bead in place.

SUMMARY

The present invention provides a vehicle wheel comprising a wheel rimhaving first and second sidewalls defining a rim trough and an openingextending through a portion of the wheel rim, a tire having a tire beadpositioned in the rim trough in engagement with the first sidewall, anda bead lock positioned in the rim trough adjacent the tire bead. Thebead lock is movable between a locked position in which the bead locksubstantially inhibits movement of the tire bead away from the firstsidewall and an unlocked position in which the bead lock permitsmovement of the tire bead away from the first sidewall. The bead lockincludes an actuator positioned in the opening and including an exposedportion accessible from outside the rim.

In one embodiment, the bead lock further includes a band positioned inthe rim trough and including two free ends movable relative to eachother. The band can include a side edge engageable with the tire bead,and the side edge can include a cut out that creates a recessed edgethat is not engageable with the tire bead. For a wider rim, the beadlock can include two bands positioned in the rim trough and spaced fromeach other, each band being positioned to substantially inhibit movementof a tire bead away from one of the sidewalls.

The bead lock can further include a tightening mechanism secured to thetwo free ends. For example, the tightening mechanism can include a winchand a cable wrapped around the winch and secured to one of the freeends. Preferably, the winch is coupled for rotation with the actuator.In order to inhibit loss of pressurized gas, the wheel can furtherinclude a seal between the actuator and the rim. In order to facilitateinsertion of pressurized gas into the wheel, the actuator can comprise atubular member having a hollow interior and a valve mechanism positionedin the hollow interior to control the passage of gas into and out of aninterior volume defined by the tire and the rim. This arrangement avoidsthe need for a separate tire inflation valve.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a bicycle having wheels embodying the presentinvention.

FIG. 2 is a perspective view of the rim and tire of one of the wheelsfrom FIG. 1.

FIG. 3 is a perspective view of the rim and tire of FIG. 2 with the tireexploded off the rim.

FIG. 4 is an exploded view of the tire and rim of FIG. 3.

FIG. 5 is a cross section of the wheel taken along line 5-5 in FIG. 3.

FIG. 6 is a cross section of the wheel taken along line 6-6 in FIG. 2with a locking mechanism in a locked position.

FIG. 7 is the cross section of FIG. 6 in perspective with the lockingmechanism in an unlocked position.

FIG. 8 is a cross section similar to FIG. 5 and showing an alternativerecessed arrangement for the locking mechanism.

FIG. 9 is a perspective view of a second embodiment of the presentinvention.

FIG. 10 illustrates a rim and tire that is a third embodiment of thepresent invention.

FIG. 11 is a cross section taken along line 11-11 of FIG. 10.

FIG. 12 is an enlarged view of the upper part of FIG. 11.

FIG. 13 is an enlarged of the lower part of FIG. 11.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

DETAILED DESCRIPTION

FIG. 1 shows a bicycle 10 that includes a front wheel 15, a rear wheel20, and a frame 25. The frame 25 has a head tube 30, a front fork 35rotationally supported by the head tube 30, a top tube 40 connected toand extending rearward from the head tube 30, and a down tube 45connected to the head tube 30 below the top tube 40 and extendinggenerally downward toward a bottom bracket (not shown) of the frame 25.A seat tube 50 extends upward from the bottom bracket and is connectedto the top tube 40, and a seat 55 is supported by the seat tube 50. Thebicycle 10 also includes a handlebar 60 for turning the front wheel 15via the fork 35, and a rear frame triangle 65 that supports the rearwheel 20. Each wheel 15, 20 includes a hub 70, a rim 75 supported by thehub 70 via spokes 80 (or other reinforcement members), and a tire 85that is attached to the rim 75.

FIGS. 2-7 illustrate the rim 75 and tire 85 of the front and rear wheelin more detail. Specifically, the illustrated rim 75 includes first andsecond sidewalls 90,92 defining a rim trough 94 and an opening 96extending through a portion of the wheel rim 75. The tire 85 has firstand second tire beads 100,102 positioned in the rim trough 94 inengagement with the first and second sidewalls 90,92, respectively (see,e.g., FIGS. 6 and 7).

The illustrated wheel further includes a bead lock 104 positioned in therim trough 94 adjacent the tire beads 100,102. The illustrated bead lock104 includes an open-ended band 106 positioned in the trough 94 andincluding two free ends 108. The illustrated band 106 is made from aspringy material that has memory (e.g., plastic, reinforced plastic,composite, spring steel, etc.) and is movable between a locked position(with the free ends 108 pulled close together) and an unlocked position(with the free ends 108 permitted to spring further apart). The band 106is configured to have a static (unstressed) shape that is larger indiameter than the diameter of the rim trough 94 so that the band 106will be biased from the locked position toward the unlock position. Inthe locked position, the band 106 is nestled into the rim trough 94 andsubstantially inhibits movement of the tire beads 100,102 away from thesidewalls 90,92. In the unlocked position, the band 106 springs out ofthe rim trough 94 and permits movement of the tire beads 100,102 awayfrom the sidewalls 90,92. For example, in the illustrated embodiment,the band 106 includes first and second side edges 112,114 that areengageable with the first and second tire beads 100,102, respectively,when the band 106 is in the locked position (FIG. 6). The first andsecond side edges 112,114 are disengageable with the first and secondtire beads 100,102 when the band 106 is in the unlocked position (FIG.7).

The bead lock 104 further includes a tightening mechanism configured toselectively move the free ends 108 toward each other. The illustratedtightening mechanism includes a winch 118 and two cables 120 wrappedaround the winch 118. One end of each cable 120 is secured to one of thefree ends 108 of the band 106. The winch 118 is secured to an actuator122 that is mounted for rotation in the opening 96 of the rim 75. Anexposed portion 124 of the actuator 122 extends through the rim 75, hasflat sides 121, and is accessible from outside the rim. That is, theflats 121 of the actuator 122 can be engaged (e.g., by a wrench or otherappropriate tool) from outside an interior volume 126 defined by the rim75 and tire 85. Two seals 127 between the actuator 122 and the rim 75inhibit the passage of gas between the actuator 122 and the rim 75. Anut 129 secures the actuator 122 to the rim 75.

By virtue of this arrangement, the winch 118 can be rotated to tightenedthe cables 120 and move the band 106 to the locked position to hold thetire beads 100,102 in engagement with the sidewalls 90,92. When it isdesired to remove the tire 85 from the rim 75, the winch 118 can berotated in the opposite direction to loosen the cables 120, which allowsthe band 106 to spring from the locked position to the unlockedposition. This arrangement facilitates movement of the band 106 into thetire when the cables 120 are released, thereby making tire installationand removal easier.

In an alternative embodiment shown in FIG. 8, the exposed portion of theactuator 123 could be recessed within the rim yet still be accessible.For example, the exposed portion could include a shaft with a hex socket125 designed to receive an allen wrench for rotating the actuator. Inthis alternative embodiment, the actuator 123 can be hollow (e.g., toreduce weight and to facilitate insertion of air into the tire), butalso require some means for preventing loss of air from the tire, suchas a valve mechanism.

The illustrated actuator 122 is made from a tubular member having ahollow interior 128. A valve mechanism 130 is positioned in the hollowinterior to control the passage of gas into and out of an interiorvolume 126. By virtue of this construction, the actuator 122 can be usedas a passage for inserting air into the wheel, and the valve mechanism130 will inhibit escape of pressurized air from the wheel unlessmanually released.

A second embodiment of the invention is illustrated in FIG. 8 andincludes a band 140 having side edges 142 with cut outs that create arecessed edge 144 that is spaced from the tire bead when the band 140 isin the locked position. These recessed edges 144 create portions of thetire beads 100,102 that are not covered by the band 140. These uncoveredportions of the tire bead are therefore subjected to air pressure fromthe pressurized air in the tire, which presses the tire bead against therim 146. The recessed edges 144 also provide a convenient place toinsert tire tools when changing a tire. That is, the recessed edges 144allow the tire tool to be used to push on the tire 85 from the outsideinto a recessed edge and lift the tire 85 off the rim 146.

A third embodiment of the present invention is illustrated in FIGS.9-13. This embodiment is particularly useful on wide rims. The thirdembodiment includes two bands 150 positioned in the rim trough 152 andspaced from each other. As with the previously-described bands, eachband 150 includes two free ends movable relative to each other, and eachband 150 is positioned to substantially inhibit movement one of the tirebeads 154 away from one of the sidewalls 156 of the rim 158. Each band150 includes a corresponding tightening mechanism 160 for moving theband 150 between the locked and unlocked positions. Preferably, the twotightening mechanisms 160 are positioned on opposing parts of the wheelso that the rim 158 stays balanced.

Various features and advantages of the invention are set forth in thefollowing claims.

1. A vehicle wheel comprising: a wheel rim having first and secondsidewalls defining a rim trough and an opening extending through aportion of the wheel rim; a tire having a tire bead positioned in therim trough in engagement with the first sidewall; and a bead lockpositioned in the rim trough adjacent the tire bead, wherein the beadlock is movable between a locked position in which the bead locksubstantially inhibits movement of the tire bead away from the firstsidewall and an unlocked position in which the bead lock permitsmovement of the tire bead away from the first sidewall, and wherein thebead lock includes an actuator positioned in the opening and including aportion accessible from outside the rim.
 2. A vehicle wheel as claimedin claim 1, wherein the tire includes two beads and the bead lockfurther includes two bands positioned in the rim trough and spaced fromeach other, each band including two free ends movable relative to eachother and each band being positioned to substantially inhibit movementone of the tire beads away from one of the sidewalls.
 3. A vehicle wheelas claimed in claim 1, wherein the bead lock further includes a bandpositioned in the rim trough and including two free ends movablerelative to each other.
 4. A vehicle wheel as claimed in claim 3,wherein the band includes a side edge engaged with the tire bead,wherein the side edge include a cut out that creates a recessed edgethat is not engaged with the tire bead.
 5. A vehicle wheel as claimed inclaim 3, wherein the bead lock further comprises a tightening mechanismsecured to the two free ends.
 6. A vehicle wheel as claimed in claim 5,wherein the tightening mechanism includes a winch and a cable wrappedaround the winch and secured to one of the free ends.
 7. A vehicle wheelas claimed in claim 6, wherein the winch is coupled for rotation withthe actuator.
 8. A vehicle wheel as claimed in claim 1, wherein theactuator is mounted for rotation relative to the rim, and wherein thewheel further includes a seal between the actuator and the rim toinhibit the passage of gas between the actuator and the rim.
 9. Avehicle wheel as claimed in claim 1, wherein the actuator comprises: atubular member having a hollow interior; and a valve mechanismpositioned in the hollow interior to control the passage of gas into andout of an interior volume defined by the tire and the rim.
 10. A vehiclewheel adapted to receive a tire having a tire bead, the vehicle wheelcomprising: a wheel rim having first and second sidewalls defining a rimtrough and an opening extending through a portion of the wheel rim; anda bead lock positioned in the rim trough adjacent but spaced from thetire bead, wherein the bead lock is movable between a locked positionand an unlocked position, and wherein the bead lock includes an actuatorcapable for moving the bead lock from the unlocked position to thelocked position, wherein the actuator is at least partially positionedin the opening and includes a portion accessible from outside the rim.11. A vehicle wheel as claimed in claim 10, wherein the bead lockfurther includes two bands positioned in the rim trough and spaced fromeach other, each band including two free ends movable relative to eachother.
 12. A vehicle wheel as claimed in claim 10, wherein the bead lockfurther includes a band positioned in the rim trough and including twofree ends movable relative to each other.
 13. A vehicle wheel as claimedin claim 12, wherein the band includes a side edge having a cut out thatcreates a recessed edge.
 14. A vehicle wheel as claimed in claim 12,wherein the bead lock further comprises a tightening mechanism securedto the two free ends.
 15. A vehicle wheel as claimed in claim 14,wherein the tightening mechanism includes a winch and a cable wrappedaround the winch and secured to one of the free ends.
 16. A vehiclewheel as claimed in claim 15, wherein the winch is coupled for rotationwith the actuator.
 17. A vehicle wheel as claimed in claim 10, whereinthe actuator is mounted for rotation relative to the rim, and whereinthe wheel further includes a seal between the actuator and the rim toinhibit the passage of gas between the actuator and the rim.
 18. Avehicle wheel as claimed in claim 10, wherein the actuator comprises: atubular member having a hollow interior; and a valve mechanismpositioned in the hollow interior to control the passage of gas throughthe tubular member.